| Part 1.The differential diagnosis value of Diffusion weighted MRI in solitary pulmonary lesionsObjective To explore the differential diagnostic value of ADC value between malignant and benign SPLs,and to compare the ADC values between different different types and differentiation degree of malignant SPLs.Methods The study was performed using 3.0T diffusion-weighted magnetic resonance imaging?DW-MRI?with b values?0,250s/mm2,600s/mm2,800s/mm2,1000s/mm2?.By using mono-exponential model,mean ADC values(ADC600,ADC800,ADC1000,ADC5b[acquired from five b values set])with different b-value sets in differentiating benign and malignant SPLs were compared,and ADC with the maximum diagnostic efficacy was screened out by comparison of area under the ROC curves?AUC?.ADC with the maximum diagnostic efficacy in different types and differentiation degree of malignant SPLs were compared.Results Ninety-three patients?93 SPLs,including 22 benign and 71 malignant cases?were enrolled in the study.ADC600,ADC800,ADC1000000 and ADC5bb all had differential diagnostic value in benign and malignant SPLs,and ADC5bb had the maximum diagnostic efficacy with AUC of 0.82,sensitivity of 83.1%and specificity of 77.3%at optimal cut-off value of 1.21×10-3mm2/s.The ADC5bb values of adenocarcinoma,squamous cell carcinoma?SqCC?and small cell carcinoma?SCC?were 1.09±0.19?×10-33 mm2/s?,0.98±0.11?×10-33 mm2/s?and 0.82±0.23?×10-33 mm2/s?,respectively.ADC5bb value of non small cell carcinoma?NSCLC,including adenocarcinoma and SCC?and small cell carcinoma was statistically significant?P<0.05?,while adenocarcinoma and SCC was not?P>0.05?.ADC5bb value in low and high grade of lung cancer were 1.12±0.23?×10-33 mm2/s?and 0.97±0.25?×10-33 mm2/s?respectively,the difference was statistically significant?P<0.05?.Conclusion ADC value has some diagnostic value in benign and malignant SPLs,and ADC5bb value has the maximum diagnostic efficacy.ADC5bb is helpful in identifying different types and differentiation degree of malignant SPLs.Part 2.MRI in solitary pulmonary lesions: correlation among apparent diffusion coefficient and multiple histopathological parametersObjective To explore independently histopathological parameters correlated with apparent diffusion coefficient?ADC?value in solitary pulmonary lesions?SPLs?,and to compare the qualitative diagnosis value of ADC value among different types of malignant SPLs.Methods The study was performed using 3.0T diffusion weighted magnetic resonance imaging?DW-MRI?.Sixty-five patients with SPLs being surgically excised were enrolled for evaluating efficiency of ADC value in distinguishing malignant and benign SPLs by receiver operating characteristic curve.Multiple histopathological parameters?cell density,nuclear-to-cytoplasm ratio,necrotic fraction,presence of mucus and grade of differentiation?were quantified and correlated with ADC values between malignant and benign SPLs by multiple linear regression,respectively.Results Malignant and benign SPLs could be distinguished by ADC value with sensitivity of 80.8% and specificity of 77.3% at threshold value of 1.21×10-3 mm2/s.Cell density??=-0.40,P<0.001?and presence of mucus??=0.77,P<0.001?were independently correlated with ADC value in malignant SPLs,by which malignant SPLs were divided into squamous cell carcinoma?n = 9?,adenocarcinomas without mucus?n = 27?and malignant tumors with mucus?n = 5?.There was no obvious correlation between histopathological parameters and ADC values in benign SPLs.The ADC values of squamous carcinomas,adenocarcinomas without mucus and malignant tumors with mucus were 0.98±0.11,1.08±0.13,1.69±0.18?×10-3mm2/s?respectively,and significant difference was found between any two of which?P<0.05?.The accurate diagnosis rate of squamous carcinomas,adenocarcinomas without mucus and malignant tumors with mucus were 100%?9/9?,82%?22/27?and 0%?0/5?respectively.The cell density of squamous carcinomas,adenocarcinomas without mucus and malignant tumors with mucus were 373±109,287±51,275±87?×400 high power field of vision?respectively,and only significant difference was found between squamous cell carcinoma and adenocarcinomas without mucus?P<0.01?.Conclusion ADC value was independently correlated with cell density and presence of mucus in malignant SPLs.Squamous carcinoma and most adenocarcinoma could be more accurately diagnosed as malignancy by ADC value.Qualitative diagnosis value of ADC value is limited in malignant SPLs with mucus and adenocarcinomas with low cell density. |
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